Synchronizing apparatus for wirebound box-making machines



Dec. 16, 1958 I c. o. RIKER 2,864,086

SYNCHRONIZING APPARATUS FOR WIREBOUND BOX-MAKING MACHINES Filed Feb. 7, 1957 3 Sheets-Sheet 1 INVENTOR.

Char/es 0. Hiker E ATTORNEYS.

C. O. RIKER Dec. 16, 1 958 SYNCHRONIZING APPARATUS FOR WIREBOUND BOX-MAKING MACHINES Filed Feb. '7, 1957 3 Sheets-Sheet 2 INVENTOR. Char/es 0. R/lrer (Zulu,

AT TOR/VEYS.

Dec. 16, 1958 c. o. RlKER 2,864,086

iSIIKH-IRQPIIZING APPARATUS FOR WIREBOUND BOX-MAKING MACHINES Filed Feb "7, 1957 :5 Sheets-Shet 3 INVENTOR. Char/es 0. Hiker M,MMM 6/ ATTOR Y5.

Unite amass SYNQHRONIZTNG APPARATUS FOR WIRE- BOUND BOX-MG MACHINES Application February 7, 1957, Serial No. 638,853

Claims. (Cl. 1146) This application relates to wirebound box making machines and particularly to an improved apparatus for synchronizing the action of the several mechanisms of the machine so that it will produce properly made boxes and crates under all conditions of operation including actuation of the manually controlled stop switch at any point during operation of the machine.

U. S. Patent No. 2,304,510 issued December 8, 1942 discloses a wirebound box making machine of the general type to which the present invention relates. In such machines, -properly assembled cleats and side material or slats are conveyed by continuously moving conveyor bands beneath a transverse bank of stapling units which drive staples astride longitudinally extending binding wires, through the side material or slats, and into the cleats to form wirebound box blanks. The conveyor bands and the stapling units are driven from a common electric motor through separate clutches. When both of these clutches are engaged, the box parts are continuously moved beneath the stapling units by the conveyor bands at a uniform rate and the staple forming and driving elements of the stapling units are reciprocated at a predetermined frequency, so that staples are driven into the moving box parts at uniform intervalsthe so-called basic staple spacing.

When the design of the particular type of box or crate blank being fabricated necessitates that the adjacent staples in each longitudinal row of staples be spaced a distance greater than this basic stapling, the clutch through which the stapling units are driven is temporarily disengaged, while the clutch through which the conveyor bands are driven remains engaged. Thus the work will continue to move past the stapling units without any staples being driven. When the stapling unit clutch is again reengaged, staples will again be driven, and the space between the first staple so driven and the last staple driven prior to disengagement of the clutch will be greater than the basic staple spacing by a distance proportional to the length of time that the stapling unit clutch was disengaged.

In the aforementioned Patent No. 2,304,510, the stapling unit clutch is controlled to vary the spacing of the staples by means of a pattern which is arranged to be actuated by a pattern bar which is rockably mounted alongside one of the conveyor bands and which is rocked first in one direction and then in the other at appropriate times by means of control elements mounted on the conveyor bands. This system was subject the disadvantage that the pattern bar was, for practical considerations, limited to a length less than that of the box blanks, so

that for each box blank along the length of the conveyor bands a plurality of control elements had to be provided for actuating the pattern bar. If the machine were'converted into making other types of box or crate blanks. the location of each of these control elements had to be changed and theset-up of the machine was therefore a time-cohsuming and expensive operation. a v

U. S. Patent No. 2,482,370 issued September 20, 1949 atent discloses a box making machine having, in lieu of the pattern bar, a remote pattern control chain for controlling the stapling unit clutch to position the staples along the box 'or crate blanks as desired. This pattern control chain is driven by and in synchronism with the convcyor bands through a clutch which is electrically controlled by a switch actuated by control elements on the conveyor bands. These control elements actuate the switch to energize the clutch and initiate movement of the pattern chain each time the leading end of a box or crate blank arrives in position to be operated on by the stapling units. The clutch is disengaged to stop the pattern chain by means of a separate switch actuated by a control element on the pattern chain each time the pattern chain completes one revolution. Other control elements spaced along the pattern chain actuate a pattern switch which controls the stapling unit clutch. The arrangement is such that alternate ones of these control elements (known as knockin pins) actuate the pattern switch to cause engagement of the stapling unit clutch and the intervening elements (known as knockout pins) actuate the switch to cause disengagement of the clutch. These pins are so positioned on the pattern chain that the stapling unit clutch is engaged and disengaged at such times that the staples are driven into the moving box blanks at the desired positions.

The stapling unit clutch is actuated by a cam on the stapling unit drive shaft units through a weak knee toggle assembly. The arrangement is such that the cam will actuate the clutch only if the two links of the toggle are aligned with each other; if the toggle is bent at its knee, it is removed from engagement with the cam. This arrangement not only derives the power for operating the clutch from the main motor through the stapling unit drive shaft, but it insures that the stapling units are always stopped at the top of their stroke, when they are out of engagement with the moving box parts.

A manual switch is provided for stopping and starting the operation of the machine. If this switch alone controlled the solenoid which actuates the toggle of the stapling unit clutch, and if the switch were thrown to the stop position when the high point of the cam on the stapling unit drive shaft is beneath the toggle, the toggle could not straighten and the stapling unit drive shaft would make a full additional revolution before the clutch was disengaged, during which time the stapling units would drive an addition transverse row of staples in the box parts. Since the conveyor bands would have stopped in the meantime, this additional transverse row of staples would be driven closer to the previous row of staples than the basic staple spacing, and the normal stapling pattern of the box would be upset, producing a possible G$cu11.!!

To avoid this difiiculty, the aforementioned Patent No. 2,304,510 disclosed a synchronizing apparatus comprising a switch which is effectively connected in paral lel with the manually operated run-stop switch. This synchronizing switch is normally closed but is opened once during each stapling cycle by a cam which is fixed on the shaft which drives the staple clinching units. When the manual switch is thrown to the stop position, nothing happens until the synchronizing switch is opened. When this occurs, the solenoid which controls the toggle through which the stapling unit drive clutch is actuated is deenergized, allowing the toggle to straighten; when the high point of the cam next rides under the toggle, the clutch is disengaged to stop the stapling units. It is imperative that the synchronizing cam be adjusted so that the solenoid is deenergized at a time when the low point of the cam is opposite the toggle. Otherwise-the togglewill not straighten and the stapling unit drive shaft will continue to rotate through another complete revolution before the clutch is disengaged.

At the same time the synchronizing switch deenergizes the stapling unit clutch solenoid, it deenergizes the solenoid which controls the conveyor band clutch and brake to bring the conveyor bands to a'stop. The actuation of the synchronizing switch takes place a brief period of time after the last transverse row of staples has been driven during which time the conveyor bands and the work carried thereby will have moved a certain distance. Another brief interval is required for the conveyor bands to come to a stop after the synchronizing switch is opened. This is due to the time required for operation of the clutch and brake, the inertia of the conveyor bands and their associated mechanism and slippage of the brake. Thus, at the time the conveyor bands come to a stop, the Work will have been advanced a certain distance past the point at which the last transverse row of staples was driven. This distance is referred to as the stopping distance.

When the manual switch is again thrown to the run position, the conveyor bands are moved a certain distance before the stapling units descend to drive the next transverse row of staples. This distance is referred to as the pick-up distance. Ideally, the sum of the stopping distance and the pick-up distance should equal the basic staple spacing, so that the stopping of the machine will not upset the stapling pattern.

The stopping distance can be varied by readjusting the synchronizing cam. For example, advancing the cam causes the conveyor bands to be stopped earlier relative to the time when the stapling units are stopped, since it increases the time after the stapling unit clutch solenoid is deenergized and the toggle controlled thereby is straightened before the toggle is engaged by the high point on the cam to disengage the stapling unit clutch. Conversely, retarding the synchronizing cam increases the stopping distance. I

The synchronizing cam is normally adjusted to maintain the desired basic staple spacing when the machine is manually stopped and restarted. However, the permissible range of setting of the cam has been extremely limited due to a number of characteristics inherent in the machine. For example, if the synchronizing cam were excessively retarded, the stapling unit clutch toggle would not have time to straighten before the high point of the cam arrived at the toggle, thus preventing the toggle from straightening until the cam rotated past the high point to present the low portion of the cam to the toggle, and the toggle would not be actuated by the cam until the high point of the cam came around again Thus, the stapling unit drive shaft would make a full additional revolution and an additional staple would be driven after the conveyor bands were stopped, and since the work was not moving during the entire interval since the next to last staple was driven, the desired basic staple spacing would not be maintained.

Another problem is involved in the use of remote pattern chains of the type disclosed in the aforementioned Patent No. 2,482,370, particularly where the manual switch is thrown to the stop position just before the last staple of a group of staples is driven--that is, just before the knockout pin on the remote pattern chain has engaged the pattern control switch. The overtravel of the conveyor bands and the remote pattern chain may cause the knockout pin to engage the switch before the conveyor bands and remote pattern chain come to a stop, throwing the pattern control switch to the position for disengaging the stapling unit clutch. Therefore, when the manual switch is again thrown to the run position, the stapling units will not function to drive the last staple in the group.

A similar difiiculty is encountered in .IHBChiHBS'iIP corporating a remote-staple wlrefeed control chain :of

the type disclosed in U. S. Patent No. 2,578,036. If the manual switch is thrown to the stop position prior to driving the last staple in the group, the overtravel of the remote wirefeed control chain may cause a knockout pin on the chain to actuate the pattern switch before the machine is stopped, thus causing the last staple to be omitted when the machine is restarted. In wirefeed pattern control systems of the type wherein the pattern chain includes an operating element corresponding to each stapling cycle during the making of a box blank, and wherein the chain is not stopped after each revolution and restarted simultaneously with the start of the next box blank, the making of an additional staple or the omission of a staple will put the pattern chain out of phase, displacing the stapling pattern on the box blanks until the machine is stopped and the pattern chain is reset.

It is the purpose of the present invention to overcome these difiiculties by providing a synchronizing apparatus which permits the operator to vary the stopping distance of the machine and achieve the desired basic staple spacing without the danger of upsetting the desired stapling pattern. Another object is that of providing such a synchronizing apparatus which is relatively simple and inexpensive in construction and which can be readily incorporated into existing wirebound box making machines without major changes in the construction thereof.

In general terms these objectives are accomplished according to the present invention by the use of two separate synchronizers, each consisting of a cam and a cooperating switch, one of the two switches being connected to control the solenoid for the stapling unit clutch and the other connected to control the solenoid for the conveyor clutch. The two cams are independently adjustable and may be set to provide any desired stopping distance necessary to maintain the basic staple spacing. The setting of the cam of the conveyor synchronizer has no interaction on the setting of the cam for the staple unit synchronizer so that the conveyor cam may be readjusted without causing the toggle of the stapling unit clutch to straighten when the high point of the cam is opposite the toggle, thereby producing an additional staple, or without delaying the stopping of the conveyor band and the remote pattern chain to the point where a knockout pin on the remote pattern chain might prematurely actuate the pattern control switch, thereby eliminating the last staple of a group of staples being made by the machine at the time the manual switch is thrown to the stop position.

In the drawings:

Figure l is a fragmentary side elevational view of the stapling section of a wirebound box or crate making machine with a portion thereof broken away to show more clearly the dual synchronizer unit embodying principles of the present invention.

Figure 2 is an enlarged side elevational view of the synchronizer.

Figure 3 is an enlarged fragmentary top plan view of the remote staple pattern control mechanism.

Figure 3A is a fragmentary top plan view of a box blank showing, more or less diagrammatically, its position relative to the staple driving station.

Figure 4 is a fragmentary side elevational view of a portion of the side of the machine opposite to that shown in Figure 1, showing means for operating the synchronizer.

Figure 5 is a fragmentary transverse sectional view of the machine taken generally along the line 5-5 of Figure 4, and showing the synchronizer in end elevation.

Figure 6 is an enlarged view of the stapling unit clutch and brake actuating mechanism the operation of which is controlled by the synchronizer.

Figure 7 is a schematic wiring diagram of theelectrical circuit of which thesynchronizeris apart.

Figure 1 shows the-light-lland side-of tbepfabrioating section of a box or crate making machine of the general type disclosed in the aforementioned Patent No. 2,304,510, with a substantial portion of its main frame cut away to show more clearly the several mechanisms controlled by the synchronizer. These mechanisms include the stapling unit clutch A keyed to the main drive shaft 2, the conveyor clutch and brake unit B keyed to shaft 4, solenoid 6 and tension spring 8 for actuating the clutch and brake unit B, staplers C and remote staple pattern control mechanism D. Figure 4 shows the stapling unit solenoid 10 with its attached toggle linkage for actuating the stapling unit clutch A and brake E for control of the main drive shaft 2.

As more fully described in the aforementioned Patent No. 2,304,510, conveyor bands 18 are driven at a predetermined speed through the change gear mechanism G (Figure 4). And, as described in detail in the aforementioned Patent No. 2,482,370, the pattern chain 20 travels at a linear speed equal to that of the conveyor bands 18, with its knockin pins 72 and knockout pins 74 alternately closing and opening the pattern switch 96 to start and stop the stapling units C.

Figures 1 and 4 show from opposite sides the dual synchronizer unit generally indicated F, which is supported on the upper inside face of the left-hand main frame 12 of the machine.

As better shown in Figures 2 and 5, the synchronizer F is comprised of two similar but independently operated mechanisms, sometimes referred to hereinafter as inner synchronizer 14 and outer synchronizer 16. Inner synchronizer 14 electrically controls the stapling unit solenoid 10 which in turn controls the actuation of stapling unit clutch A and brake E to start and stop the stapling units C. Outer synchronizer 16 electrically controls solenoid 6 which, with tension spring 8, actuates the conveyor clutch and brake unit B to start and stop the conveyor bands 18 and the pattern chain 20, which is connected to the conveyor band drive through a clutch 86 (Figure 3) which is electrically controlled by start switch 22 (Figure 1) and stop switch 24 (Figure 3).

As may be seen in Figures 2 and 5, the two synchronizers 14 and 16 are supported on a plate 26 secured to the inner face of the left-hand frame 12 of the machine. Spaced apart vertically in the lower portion of the plate 26 are a pair of outwardly projecting rectangular posts 23 each of which is provided with a pair of bores for slidably su porting vertical rods 30 and 32 (Figure 5) of inner and outer synchro-nizers 14 and 16 respectively. Secured near the upper ends of rods 30 and 32 and projecting perpendicularly therefrom are rectangular bars 34 and 36, respectively. These bars extend rearwardly of the machine-4. e. toward the right as viewed in Figures 1 and 2and carry near their outer ends set screws 38 and 40, respectively, which are adjustably threaded through the bars and engage the push buttons of electric switches 42 and 44 respectively. The upper ends of rods 30 and 32 are pivotally attached to the plungers of their respective solenoids 46 and 48 while their opposite ends support small follower rollers 50.

These rollers 50 respectively ride on the periphery of earns 52 and 54 in the inner and outer synchronizing units 14 and 16. The cams 52 and 54 are adjustably mounted on a shaft 56 which is driven in a counterclockwise direction from the main drive shaft 2, through a sprocket 5S keyed thereto, a chain 60 trained on sprocket 53 on a sprocket 62 keyed on a shaft 66, another sprocket keyed to the shaft 66 and a chain 63 trained on sprocket 64 and on a sprocket 70 keyed to the shaft 56.

The electrical circuit connections of the synchronizing units are shown in Figure 7.

As may be seen in that figure, pressing of start push button H connects the winding of the motor relay Y across two conductors of the three-wire service line '71. This-energizes the motor relay Y, closing its normally open contacts "-Y1, Y2 and Y3.to.supply current 'to the-- motor 76 (see also Figure 1), causing it to run con tinuously.

Closure of the relay contacts Y1 and Y2 also supplies current through the leads 75 and 77 to the remote pattern control mechanism D, shown at the upper right in Figure 7, and the synchronizing circuit, shown in the lower portion of that figure. When the machine control lever switch I (at the lower left in Figure 7) is in the stop position K the relay U is energized through the switch contacts T, T3 and T4. Energization of the relay U is maintained even when the lever switch I is moved to the run position K1, a circuit to the relay winding being completed through its contacts U1 and through the contacts T of lever switch J, which are closed in both the stop position K and the run position K1.

Movement of the lever switch I to the run position K1 completes circuits through its normally open contacts T1 and T2 and through the contacts U2 and U3 of relay U to energize the windings of the relays V and W, the solenoids 46 and 48 of the synchronizers 14 and 16, and the solenoid 6 of the conveyor clutch and brake unit B.

Energization of the conveyor clutch and brake solenoid 6 causes the conveyor bands 18 to be driven by clutching of sprocket 73 to shaft 4 which is connected to the conveyor drive shaft 82 through the change gear mechanism G (Figure 4), a sprocket 30 (Figure 1) driven there by, a chain 81 trained thereon and on a sprocket 84 keyed on the conveyor drive shaft 82. The conveyor drive shaft 32 drives the magnetic clutch unit 86 of staple pattern control mechanism D (Figures 1 and 3) through a sprocket 83, chain 35, sprocket 87, shaft 8?, sprocket 91, chain 93 and sprocket 95. Thus whenever conveyor bands 18 are driven in the direction indicated by the arrow L (Figure 1) and the magnetic clutch unit 86 is engaged, the staple pattern chain 20 will be driven in the direction indicated by the arrow in Figure 3.

Energization of the relays V and W (Figure 7), as above described, also energizes the winding of relay X through the relay contacts U4, W2 and V1 and the contacts T1 of lever switch J. Energization of the relay X closes its contacts X3 to supply current to the stapling unit clutch solenoid 10 through the synchronizing switch 42 whenever the pattern switch 96 is closed by one of the knockin pins 72 (Figure 3) on the pattern chain 20. Energization of the solenoid 10, as shown in broken lines in Figure 6, retracts its plunger 98 and collapses the horizontal toggle unit 100 as well as the vertical toggle unit 102 connected thereto. This removes the roller 104 of the vertical toggle unit 102 from contact with the control cam 106 keyed on the main shaft 2, allowing the lever 168 and the shaft 110 on which it is fixed to be rocked in a counterclockwise direction by the spring 111, releasing the brake E (Figures 4 and 7) and the brake 118 (Figure 7) of the stapling unit clutch A (Figure 1), causing it to engage and clutch the drive shaft 2 to the sheave 112. The stapling units C will thus be cyclically operated to drive staples into the moving work upon each rotation of shaft 2 until the pattern switch 96 is actuated by a knockout block 74 on pattern chain 20.

If, at any time during operation of the machine, the operator moves the machine control lever I to the stop position K, the relays V and W will be deenergized and the opening of their contacts will in turn deenergize the synchronizer solenoids 46 and 43, allowing their respective rods 30 and 32 (Figure 5) to drop, so that the rollers 50 engage their respective cams 52 and As may be seen in Figure 2, cam 52 of synchronizer 14 is shaped to provide at its periphery a pair of ,diarnetrically opposed recessed portions 114 which allow SLlfilcient downward movement of rod42. When this occurs the stapling unit clutch solenoid 10 is deenergized, allowing its plunger 98 to drop and straighten horizontal toggle 100 and vertical toggle 1.02, as shown in full lines in Fi ure '6, at a time when the low portion of the cam 10.6 is opposite the toggle 102. When the high'poinfon th' cam 106 reaches the toggle 102, counterclockwise movement will be imparted to shaft 110 through lever 108, causing the stapling unit clutch A to be disengaged and the brake E to be applied, stopping the stapling units at the top of their stroke.

As may also be seen in Figure 2, cam 54 of synchronizer 16 has similarly shaped recessed portions 116 which are normally set in a retarded position relative to the recessed portions 114 of cam 52. When solenoid 48 is deenergized, as aforesaid, to free the rod 32 for downward movement, the recessed portions 116 of cam 3 permit sutficient downward movement of rod 32 to open the synchron'izing switch 44, deenergizing solenoid 6 and permitting tension spring 8 to cause a declutching and braking action of the conveyor band clutch and brake unit B, stopping the conveyor bands 18.

Figures 3 and 3A show diagrammatically the relationship between the remote pattern chain 20 and a fragmentary portion of the trailing end of a box blank as the machine is stopped. These figures illustrate a condition wherein the machine control lever J is moved to the stop position K during the machine cycle in which the second staple M (Figure 3A) of a group of three staples was being driven in the box blank at the basic staple spacing S.

The line N indicates the staple driving station and illustrates the position of the box blank relative thereto when the machine is stopped. The distance Z between this line N and the last staple M which was driven before stopping is the so-called stopping distance of the machine.

When lever switch I is again moved to the run posi tion' K1, solenoid 6 is energized instantly through contacts T1, of switch I and contacts U2 of relay U. This actuates the conveyor band clutch and brake unit B to communicate instantaneous movement to the conveyor bands 18. Staple pattern chain 20 will also start moving instantly and in unison with conveyor band 18 in the manner described hereinbefore.

The energization of stapling unit clutch solenoid 10 is not instantaneous but involves a slight delay during which the following operations occur: closure of contacts T1 and T2 of lever switch I energizes relays V and W through the closed contacts U3 and U2 of relay U; the energization of relays V and W closes their contacts V1 and W2, energizing relay X through the closed contacts U4 of relay U; this closes the relay contacts X1 and energizes solenoid it} to start the stapling units C. During this brief period of delay before the stapling units C are started, the conveyor bands 18 will already have moved a certain distance, and will move an additional distance before the staple forming and driving elements move downwardly to drive the next staple R (Figure 3A). This total movement is the pick-up distance, which is designated Z1 in Figure 3A.

From the discussion hereinabove, it will be apparent that there are several important relationships which should be maintained. For example, the stopping distance Z and the pickup distance Z1 should be such that their sum equals the basic staple spacing S, so that the first staple R driven after machine operation is resumed is spaced from the preceding staple M by the same distance as though the machine had been running continuously. In addition, it is necessary that the angular position of the cam 52 be such that the switch 42 will be actuated to dcenergize the solenoid 1t) and straighten the toggle 1192 at a time when the low portion of'the cam 1:16 is opposite the toggle. This prevents making an extra staple. Moreover, it is important that .the stopping distance Z be short enough that the conveyor bands 18 and the synchronously driven pattern chain 20 will come to a stop before the knockout pin 74 (Figure 3) has actuated the pattern switch 96. This prevents omission of the last staple R in the group of three staples being .driven at the time the.lever switch I .is moved .to the stop ,position.

The pickup distance Z1 is determined by the inherent characteristics of the machine and is not readily adjustable. However, the synchronizer described herein makes it a simple matter to vary the stopping distance Z through a wide range Without precluding any of the objectives mentioned above. This is accomplished merely by adjusting the relative angular positions of the synchronizer cams 52 and 54.

It is also important that the stapling unit solenoid 10 be deenergized prior to and within the same cycle as the solenoid 5 of conveyor clutch and brake unit B. To insure this sequence ofoperation, a bridging circuit is provided to keep solenoid 6 of conveyor clutch and brake unit B energized until after stapling unit solenoid 10 is deenergized. This circuit is provided through contact X2 of relay X which remains closed until switch 42 of synchronizer 14 is actuated to break the circuit through contacts X3 and X1 to relay X. Thus the conveyor clutch and brake unit B cannot be actuated to stop the conveyor bands before the declutching and braking cycle of the stapling unit clutch A and brake E is started. This limits the stopping distance of the machine and helps to insure achievement of the proper stapling pattern.

The winding of the relay V is connected in parallel with the solenoids 46 and 48 of the synchronizers 14 and 16 so that the relay V is deenergized to open its contacts V1 simultaneously with the dropping of the solenoid plungers when the lever switch I is thrown to the stop position K. The opening of these contacts V1 prevents a sneak circuit to relay X through contacts X2, U2, V1, W2 and U4, which would otherwise keep relay X energized 'after opening of switch 42 of synchronizer 14.

In the event of an emergency requiring immediate stopping of the conveyor bands, the lever switch J is thrown to the emergency stop position K2. This opens its contacts T and 'deenergizes all of the relays and solenoids in the entire synchronizing circuit. The conveyor band clutch and brake unit B is immediately declutched and braked to stop the conveyor bands 18. For immediate stoppage of the entire machine including the stapling units, the stop button H1 of the motor switch is pressed to deenergize the relay Y, stopping the motor '76 as well as deenergizing the synchronizing circuit.

From the foregoing description, it will be apparent that the present invention accomplishes the aforementioned and other desirable objectives. However, it should be emphasized that the particular embodiment of the invention which is shown and described herein is intended as merely illustrative of the principles thereof rather than as restrictive of the coverage of this patent, which is limited only by the appended claims.

I claim:

1. In a box-making machine of the type having stapling units driven cyclically through a stapling unit drive means and conveyors driven through a conveyor drive means for transporting assembled box parts past said stapling units to cause staples to be driven therein at a predetermined spacing, and a manually operated control switch for stopping said machine, the combination therein of means for synchronizing the stopping of said conveyors and stapling units comprising a pair of synchronizer units, one'connected for effective control of said stapling unit drive means and the other connected for control of said conveyor clutch drivemeans, and timing means under the control of said manually operated switch foractuating said synchronizer units at different times.

2. In a box-making machine of the type having stapling units driven cyclically through an electrically controlled stapling unit drive means and a conveyor driven through an electrically controlled conveyor drive means for transporting assembled box parts past said stapling units to cause staples .to be driven thereinat a predetermined spaciugaudamauually bpcratedswitchjor stopping Said machine, the combination therein of means for synchronizing the stopping of said conveyor and stapling units comprising a pair of synchronizer units, each including an electric switch, one of said switches being connected for effective control of said stapling unit drive means and the other of said switches being connected for effective control of said conveyor drive means, and cam means conditioned by movement of said manually operated switch to the stop position for respective actuation of said electric switches at difierent times.

3. In a box-making machine of the type having stapling units driven cyclically through an electrically controlled stapling unit drive means and a conveyor driven through an electrically controlled conveyor drive means for transporting assembled box parts past said stapling units to cause staples to be driven therein at a predetermined spacing, and 'a manually operated switch for stopping said machine, the combination therein of means for synchronizing the stopping of said conveyor and stapling units comprising a pair of synchronizer units, each including an electric switch, one of said switches being connected for effective control of said stapling unit drive means and the other of said switches being connected for effective control of said conveyor drive means, a pair of timing cams mounted on a shaft driven through one of said drive means, said cams having actuating portions effectively offset relative to one another, and a pair of cam followers conditioned by movement of said manually operated switch to the stop position for respective actuation of said switches to initiate stopping of said stapling units and said conveyor upon movement of said cam followers by the actuating portions of said cams.

4. In a box-making machine of the type having stapling units driven cyclically through an electrically controlled stapling unit clutch and a conveyor driven through an electrically controlled conveyor clutch for transporting assembled box parts past said stapling units to cause staples to be driven therein at a predetermined spacing, and a manually operated switch for stopping said machine, the combination therein of means for synchronizing the stopping of said conveyor and stapling units comprising a pair of synchronizer units, each including an electric switch, one of said switches being connected for effective control of said stapling unit clutch and the other of said switches being connected for effective control of said conveyor clutch, a pair of timing cams mounted on a common shaft driven through one of said clutches, said cams having recessed portions and being adjustable to various rotational positions relative to one another to cause one of said recessed portions eifectively to lead the other by a desired angle, a pair of cam followers adapted to ride respectively on said cams, solenoid means connected for control by said manually operated switch and mechanically coupled to said cam followers to maintain them out of engagement with said cams except when said manually operated switch is thrown to the stop position, said electric switches being arranged for respective actuation by said cam followers when said cam followers ride into said recessed portions, said switches being connected for respective control of said clutches to initiate disengagement of the same when so actuated.

5. In a box-making machine of the type having stapling units driven cyclically through an electrically controlled stapling unit clutch and a conveyor driven through an electrically controlled conveyor clutch for transporting assembled box parts past said stapling units to cause staples to be driven therein at a predetermined spacing, and a manually operated switch for stopping said machine, the combination therein of means for synchronizing the stopping of said conveyor and stapling units comprising a pair of synchronizer units, each including an electric switch, one of said switches being connected for effective control of said stapling unit clutch and the other of said switches being connected for effective control of said conveyor clutch, a pair of timing cam elements rendered effective by said manually operated switch to actuate said pair of synchronizer switches respectively at different times and electrical relay means controlled by the switch which controls the stapling unit clutch and including contacts effectively connected in parallel with the switch which controls the conveyor clutch through which said conveyors are driven to prevent disengagement of the conveyor clutch' before disengagement of the stapling unit clutch is initiated.

No references cited. 

